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Spatial / Temporal Features of Antarctic Climate Change

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Advances in Atmospheric Sciences 1996年第3期13卷 375-382页

作者：葛玲梁佳兴陈毅良 Department of meteorology Nanjing Institute of MeteorologyNanjing 210044

Bused on January 1962-October 1993 mean value series of monthly mean temperature anomalies of 16 Antarctic stations on 10 standard isobanc surfaces from the surface to the 30 hPa,long term trends and periodic features of climate changes from the troposphere to the lower stratosphere over the Antarctic region are investigated by maximum entropy power spectrum analysis,and the relation between climate change of the stratosphere (troposphere) and tolal ozone (southern 500 hPa circulation) is discussed.

关键词： Antarctic Climate change: Long term trend, Periodicity Total ozone

Elevation Influence on Rainfall and a Parameterization Algorithm in the Beijing Area

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Journal of Meteorological Research 2019年第6期33卷 1143-1156页

作者： Linye SONG Mingxuan CHEN Feng GAO Conglan CHENG Min CHEN Lu YANG Yong WANG institute of Urban meteorology China Meteorological AdministrationBeijing 100089China Central institute for meteorology and Geodynamics Vienna A-1190Austria

Using a high-density automatic weather stations(AWS)dataset of hourly rainfall observations,the present study investigates the relationship between rainfall and elevation in the Beijing area,and further proposes a rainfall amount dependent parameterized algorithm considering the elevation effect on rainfall on hourly *** parameterization equation is defined as a segmented nonlinear model,which calculates the mountain rainfall as a function of valley rainfall *** show that there exists an evident enhancement of rainfall amount by elevation effect in the Beijing *** particular,larger rainfall amount is generally found in higher mountains,especially for slight rain and moderate ***,six representative station pairs located in valleys and on mountains respectively are selected to estimate the values of optimal parameters in the parameterization *** parameterization algorithm of elevation dependence can produce a reduction in the root-mean-square error and obtain a much closer mountain rainfall total to the observations compared with those using no elevation ***,the spatial distribution of rainfall is more realistic and accurate in mountainous terrain when elevation dependence is *** study helps to understand the variability of rainfall with complex terrain in the Beijing area,and gives a possible way to parameterize rainfall–elevation relationship on hourly timescale.

关键词： rainfall elevation influence parameterization algorithm Beijing

A Grid-nested, Water-bearing, N-Level Primitive Equation Model

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Chinese Science Bulletin 1993年第17期38卷 1464-1469页

作者：郑良杰夏大庆 Beijing institute of Applied meteorology

In order to forecast and research the characteristics of cloud physics in large-scale systems, we have developed a grid-nested, water-bearing, N-level primitive equation model. The conventional large-scale numerical model is run in the coarse-grid region, and the water-bearing model may be run in the fine-grid region. The values on boundary grids

关键词： model primitive equation cloud physics.

Statistically Extrapolated Nowcasting of Summertime Precipitation over the Eastern Alps

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Advances in Atmospheric Sciences 2017年第7期34卷 925-938页

作者： Min CHEN Benedikt BICA Lukas TCHLER Alexander KANN Yong WANG institute of Urban meteorology China Meteorological Administration Beijing 100089 China Central institute for meteorology and Geodynamics Vienna 1190 Austria

This paper presents a new multiple linear regression（MLR） approach to updating the hourly, extrapolated precipitation forecasts generated by the INCA（Integrated Nowcasting through Comprehensive Analysis） system for the Eastern *** generalized form of the model approximates the updated precipitation forecast as a linear response to combinations of predictors selected through a backward elimination algorithm from a pool of predictors. The predictors comprise the raw output of the extrapolated precipitation forecast, the latest radar observations, the convective analysis, and the precipitation analysis. For every MLR model, bias and distribution correction procedures are designed to further correct the systematic regression errors. Applications of the MLR models to a verification dataset containing two months of qualified samples,and to one-month gridded data, are performed and evaluated. Generally, MLR yields slight, but definite, improvements in the intensity accuracy of forecasts during the late evening to morning period, and significantly improves the forecasts for large thresholds. The structure-amplitude-location scores, used to evaluate the performance of the MLR approach,based on its simulation of morphological features, indicate that MLR typically reduces the overestimation of amplitudes and generates similar horizontal structures in precipitation patterns and slightly degraded location forecasts, when compared with the extrapolated nowcasting.

关键词： Precipitation forecast convective Eastern correction verification backward qualified degraded morning

Construction of Vertical Wind Profile from Satellite-Derived Winds for Objective Analysis of Wind Field

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Advances in Atmospheric Sciences 1992年第2期9卷 237-246页

作者： P.N.Mahajan D.R.Talwalkar S.Nair S.Rajamani Indian institute of Tropical meteorology Pune-411008Indian Institute of Tropical Meteorology Pune-411008Indian Institute of Tropical Meteorology Pune-411008Indian Institute of Tropical Meteorology Pune-411008

During summer Monex-79, a variety of observing systems viz. research ships, research aircrafts, constant pressure balloons and geostationary satellite etc. were deployed, besides the regular conventional observations. The purpose of these additional systems was to make the best possible data for the studies on various aspects of monsoon circulation. The present study is aimed at the construction of vertical wind profile using cloud motion vectors obtained from GOES (I-O) satellite and to examine whether the constructed wind profiles improves the representation of the monsoon system, flow pattern etc. in the objective analysis. For this purpose, climatological normals of the wind field are considered as the initial guess and the objective analyses of the wind field are made with, first using only data from conventional observations over land areas, subsequently including the constructed winds from cloud motion vectors. These analyses are then compared with the standard analyses of wind field obtained from Quick Look Atlas by T. N. Krishnamurti et al. (1979).It is inferred that satellite estimated mean wind profiles show good agreement with the mean wind profiles of the research ships with RMS errors less than 5 mps below 500 hPa and less than 8 mps above 500 hPa. It is further inferred that the inclusion of constructed winds shows a positive impact on the objective analysis and improvement is seen to be more marked in the data-sparse region of the Arabian sea. Analyses which include the constructed winds show better agreement with the standard analysis, than the analyses obtained using only conventional winds. Thus, results of our study suggest that the wind profiles constructed using cloud motion vectors are of potential use in objective analysis to depict the major circulation features over the Indian region.

关键词： Construction of Vertical Wind Profile from Satellite-Derived Winds for Objective Analysis of Wind Field Wind

ON THE SOLUTION OF THE MODEL OF TWO CO-AFFECTED SPECIES

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Applied Mathematics and Mechanics(English Edition) 1994年第2期15卷 135-146页

作者：张为付吕荣庆 The Air Force institute of meteorology Nanjing

A model of two co-affected species with diffusion system in the population dynamics was discussed, where the birth functions had the characteristic index decline. Then, two kinds of parameters were introduced. One was circumstance factors αi which were connected with natural resources and the other was birth parameters βi which could be controlled. By constructing the upper-lower solutions, the existence, uniqueness and the local stability of equilibrium solution of the model were proved. It is shown that the birth parameter βi determine the developing tendency when other parameters are comparatively stable.

关键词： Differential equations Nonlinear equations

EFFECT OF INSTABILITIES OF FLOW ON MESOSCALE PREDICTABILITY OF WEATHER SYSTEMS

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Journal of Hydrodynamics 2011年第2期23卷 193-203页

作者： LUO Yu ZHANG Li-feng institute of meteorology PLA University of Science and Technology Nanjing 211101

The numerical solution of Boussinesq equations is worked out as an initial-value problem to study the effect of the instabilities of flow on the initial error growth and mesoscale predictability. The development of weather systems depends on different dynamic instability mechanisms according to the spatial scales of the system and the development of mesoscale systems is determined by symmetric instability. Since symmetric instability dominates among the three types of dynamic instability, it makes the prediction of the associated mesoscale systems more sensitive to initial uncertainties. This indicates that the stronger instability leads to faster initial error growth and thus limits the mesoscale predictability. Besides dynamic instability, the impact of thermodynamic instability is also explored. The evolvement of convective instability manifests as dramatic variation in small spatial scale and short temporal scale, and furthermore, it exhibits the upscale growth. Since these features determine the initial error growth, the mesoscale systems arising from convective instability are less predictable and the upscale error growth limits the predictability of larger scales. The latent heating is responsible for changing the stability of flow and subsequently influencing the error growth and the predictability.

关键词： instabilities of flow mesoscale system predictability initial errors

VARIABILITY OF DAILY PRECIPITATION IN CHINA(1980-1993): PCA AND WAVELET ANALYSIS OF OBSERVATION AND ECMWF REANALYSIS DATA

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Chinese Journal of Oceanology and Limnology 2000年第2期18卷 117-110,118-125页

作者：崔茂常朱海练树民 KlausArpe LydiaDümenil institute of Oceanology Chinese Academy of Sciences Qingdao China IASG Institute of Atmospheric Physics Chinese Academy of Sciences Beijing China max-planck institute for meteorology Hamburg Germany

In this study, principal component analysis(PCA) and complex Morlet wavelet transform were used with daily rainfall in China for the period 1980-1993(1 May-31 Dec.) from observation and ECMWF reanalysis to study its variability and evaluate the validation of reanalyzed precipitation. The results showed that northward movement of the summer rain belt was a wavelike propagation, which was always accompanied by rainfall breaks and could be treated as one event under time scale of about 1 month only. The first 4 EOFs accounted for 28% and 35% of total variance from observation and reanalysis, respectively, and were roughly consistent with each other. The first and third EOFs for observation mainly represented interweekly, interseasonal and interannual variations and contained some summer intraseasonal fluctuations also. The second and fourth ones mainly represented some rather strong summer intraseasonal fluctuations for a paticular year and contained interweekly, interseasonal and interannual variations also. Although there is still room for improvement, the ECMWF reanalysis is the best available dataset with global coverage and daily variability.

关键词： daily precipitations in China ECMWF reanalysis PCA and wavelet analysis

A performance evaluation of remotely sensed sea surface salinity products in combination with other surface measurements in reconstructing three-dimensional salinity fields

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Acta Oceanologica Sinica 2017年第7期36卷 15-31页

作者： CHEN Jian YOU Xiaobao XIAO Yiguo ZHANG Ren WANG Gongjie BAO Senliang Beijing institute of Applied meteorology Beijing 100029China institute of meteorology and Oceanography PLA University of Science and TechnologyNanjing 211101China

Several remotely sensed sea surface salinity（SSS） retrievals with various resolutions from the soil moisture and ocean salinity（SMOS） and Aquarius/SAC-D missions are applied as inputs for retrieving salinity profiles（S） using multilinear regressions. The performance is evaluated using a total root mean square（RMS） error, different error sources, and the feature resolutions of the retrieved S fields. In the mixed layer of the salinity, the SSS-S regression coefficients are uniformly large. The SSS inputs yield smaller RMS errors in the retrieved S with respect to Argo profiles as their spatial or temporal resolution decreases. The projected SSS errors are dominant, and the retrieved S values are more accurate than those of climatology in the tropics except for the tropical Atlantic, where the regression errors are abnormally large. Below that level, because of the influence of a sea level anomaly, the areas of high-accuracy S values shift to higher latitudes except in the high-latitude southern oceans, where the projected SSS errors are abnormally large. A spectral analysis suggests that the CATDS-0.25° results are much noisier and that the BEC-L4-0.25° results are much smoother than those of the other retrievals. Aquarius-CAP-1° generates the smallest RMS errors, and Aquarius-V2-1° performs well in depicting large-scale phenomena. BEC-L3-0.25°,which has small RMS errors and remarkable mesoscale energy, is the best fit for portraying mesoscale features in the SSS and retrieved S fields. The current priority for retrieving S is to improve the reliability of satellite SSS especially at middle and high latitudes, by developing advanced algorithms, combining both sensors, or weighing between accuracy and resolutions.

关键词： soil moisture and ocean salinity Aquarius sea surface salinity vertical retrieval feature resolution